Logical negation, which reverses the truth value of a sentence, is essential to human communication. Children learning English begin saying no around their first birthday, but their first uses are limited to particular social functions, like rejection. Not until nearly a year later do children begin producing and understanding clearly logical uses of negation words. One possible cause of this delay is that children struggle to learn the mapping between the concept of negation and negation words—a linguistic bottleneck. Alternatively, children might struggle to learn the concept itself—a conceptual bottleneck. We tested these hypotheses by comparing negation production in typical English-learners and internationally-adopted preschoolers. Adopted preschoolers are more conceptually mature than infants but face a similar language-learning task. If first-language learners face a conceptual bottleneck, then adoptees should learn negation faster. If the main bottleneck is linguistic, then the two groups should learn negation at the same rate relative to their acquisition of English. In Study 1 we found that according to parent reports on the MB-CDI, international adoptees and language-matched infant first-language learners begin producing no and not at the same point in vocabulary growth. In Study 2, we examined children’s production of logical denial negation in large-scale aturalistic corpora. We found that adopted preschoolers’ and language-matched infants’ production of denials increased at the same rate as the mean length of children’s utterances increased. The matching patterns of negation acquisition in internationally-adopted preschoolers and first-language-learning infants support a linguistic, not conceptual, bottleneck on the acquisition of negation.
In order to learn the meanings of words, children must solve two potentially separable tasks: to learn the mappings between words and their meanings, and to learn the concepts that underlie those meanings. This chapter examines the acquisition of negation by taking each of these tasks in turn. We argue that children's limited early uses of negation words reflect limited early meanings, but that the slow emergence of logical negation can be fully explained by the difficulty of learning the linguistic mappings, without the need to appeal to additional conceptual difficulty. Further, we argue that children are in posession of at least a precursor to the concept of logical negation—contrary—by 17 months. Even so, it remains possible that some conceptual development occurs between when children first use the word "no", and when they finally learn its truth-functional logical meaning, and we spell out a proposal for how the logically limited concept contrary could contribute to the construction of the concept negation. Finally, to test the possibility that langauge itself plays a role in the construction of negation, we propose that future work compare children's acquisition of negation across languages with varying mappings between words and meanings.
preprint publisher downloadPrevious research has suggested several stages for children’s production of negation. Some researchers have argued that the order of morpheme production follows a "no-not-n't" cline. Others have hypothesized stages where "no" appears outside the sentence and a stage where "can't" and "don't" are learned as unanalyzed wholes because "can" and "do" are not produced separately. In this study we bring more corpus data and novel analyses to bear on these hypotheses. The results suggest that "no" is produced earlier but "not" and "n't" are produced around the same time. We do not find evidence for a presentential stage or a stage where negative auxiliaries like "can't" and "don't" are produced without the positive forms like "can" and "do". Our findings are compatible with simultaneous development of frequent negative forms with a production bottleneck that favors shorter utterances like "no" to appear earlier.
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